Field of the Invention
The present invention relates to an endoscopic treatment tool for collecting a foreign substance in a body.
Background Art
In the related art, endoscopic treatment tools, which are endoscopically inserted into a body and collect a foreign substance such as a calculus formed inside the body such as the bile duct, are known. For example, PCT International Publication No. 2012/141213 discloses an endoscopic treatment tool, which includes a basket part constituted a plurality of helical elastic wires and in which a calculus is collected by being accommodated inside the basket part. In the endoscopic treatment tool disclosed in PCT International Publication No. 2012/141213, in order to prevent overall of the basket part from being bent and collapsing, the basket part is provided with a support member. A distal end of the support member is fixed to a distal end of the basket part and the support member is disposed inside the basket part. A proximal end of the support member is disposed along a proximal portion of the basket part and is inserted into a flexible sheath.
When a large calculus is collected by an endoscopic treatment tool having such a basket part, for example, in regard to a relationship between the size of the basket part accommodating the calculus and the size of a lumen, there are cases where so called incarceration such that the basket part is caught inside the bile duct and disabling advance and retract inside the bile duct occurs. In a case where incarceration occurs, treatment of crushing (emergency crushing) a calculus inside the basket part is performed by a calculus crushing apparatus disclosed in Japanese Unexamined Patent Application, First Publication No. H6-133978. In the calculus crushing apparatus disclosed in Japanese Unexamined Patent Application, First Publication No. H6-133978, in a case where incarceration occurs, after a proximal end portion of an operating wire of the treatment tool exposed to the outside of the body is cut, an endoscope and the flexible sheath through which the treatment tool is inserted in a state where a calculus is accommodated inside the basket part are removed from the inside of the body. Next, a cut portion of the operating wire of the treatment tool is covered with a coil sheath of the calculus crushing apparatus, and the coil sheath is inserted into the body to reach a proximal end of the basket part. Thereafter, the cut portion of the operating wire is wound on a proximal end side of the coil sheath such that the basket part is taken into the coil sheath. Accordingly, wires of the basket part strongly tighten the calculus and crush the calculus. When the calculus is crumbled into small pieces through the crushing, the basket part becomes to be capable of removing from the inside of the bile duct.